1. Field of the Invention
The present invention relates to a method for producing a reinforcing stainless steel wire--aluminum alloy composite structure and a product thereof and more particularly, to a surface treatment of a reinforcing stainless steel wire with carbon nitride for use in an aluminum alloy composite structure for preventing the reduction in strength of the stainless steel wire.
2. Description of Related Art
Generally, a boundary reaction between a reinforcing fiber and a matrix in a fiber-matrix composite structure influences the mechanical property and the reinforcing effect thereof. Particularly, the wetability between the matrix and the reinforcing fiber critically influences the properties of its composite structure. Since the reactivity of the reinforcing fiber and the aluminum matrix is serious, the precipitation of a secondary phase generated by contact reactions causes a reduction in the mechanical properties.
Also, if the steel wire is used as the reinforcing fiber, the contacting reaction of the steel wire and the aluminum alloy matrix produces brittle Fe.sub.m Al.sub.n compound since the solubility of steel with aluminum is very low such as, for example, 0.01 to 0.12 weight % at 275.degree. to 600.degree. C. Specifically, n-phase Fe.sub.2 Al.sub.5 layer is produced at the boundary surface of steel and aluminum, and its characteristics diffuses very fast through the vacancy and grows at a high speed at 700.degree. to 750.degree. C.
Generally, an increase of the thickness of the boundary reaction layer causes a decrease in the tensile strength and the fracture elongation of the composite structure. However, if the thickness of the boundary reaction layer is less than 10 .mu.m, it does not influence the cold deformation.
The growth of this metal compound (Fe.sub.m Al.sub.n) layer depends on the composition of the aluminum melt and the reinforcing wire. If Si of 2 to 12% is put into the aluminum melt, the growth of this metal compound can be controlled and also if Cr, Ni, Cu, Si, C and O.sub.2 is added to the steel composition, the product of Fe.sub.m Al.sub.n compound is controlled. Furthermore, if Mo and W exist the growth of this Fe.sub.m Al.sub.n compound is controlled by the diffusion thereof. Also, if Co electric gilding can be reduced the thickness of this Fe.sub.m Al.sub.n compound.